these 4 derivations will be built:
  /nix/store/cglmfy5dli4smizj94gi3rfw8jlqr4s6-Cargo.toml.drv
  /nix/store/sxl4i025kygim1k7jfl15jnzv3rgm7qf-source.drv
  /nix/store/4lsjm7dv3p8s6n82givrvm4h6igdd103-harmonia-deps-3.1.0.drv
  /nix/store/8g2dh6lh5mdz60fvwlcd1r6qd5qpfyb0-harmonia-3.1.0.drv